Project Summary The long term goal of this project is to develop a definitive and adequate assessment of the diagnostic potential and non-mortality outcomes of breast cancer screening in supplement to mammography for women with dense breasts. The purpose of achieving this goal is to provide evidence to adjust the current inadequate assessment guidelines that modulate care provided and inform insurance coverage, especially in lower resource settings. Breast density is one of the most significant risk factors for the development of breast cancer, and breast density is mandatorily reported to patients in some respect in 30 states. If information identifying increased risk is provided to patients, options for additional care should be provided simultaneously. Supplemental screening measures developed for use by women with an increased risk for breast cancer include breast ultrasound (US), breast magnetic resonance imaging (MRI), digital breast tomosynthesis (DBT) and molecular breast imaging (MBI). Studies have shown that these modalities have an increased specificity compared to mammography, and in conjunction with mammography have an increased sensitivity for tumors. However, with minimal use and short times from FDA approval for this use, it has not been shown that there has been a significant reduction in mortality with use of these modalities. Longitudinal studies assessing the efficacy of breast cancer mortality mitigation are thought to be necessary to show benefit of these modalities, but are costly and time consuming. Therefore, other methods for assessing the utility and benefit of novel technology are required, and will allow for more efficient implementation of technologies that prove beneficial. Regardless of current guidelines with insufficient evidence to recommend use of novel technologies, the Mayo Clinic is in the process of implementing use of screening DBT and MBI in routine care for patients who are the most likely to benefit from these modalities; those who are at increased risk of breast cancer. The Mayo Clinic also has a 27 county wide data sharing effort, the Rochester Epidemiology Project, which allows data abstraction from all patients consenting to EMR research. To that end, the purpose of this proposal is to characterize diagnostic potential (Aim 1) and non-mortality outcomes (Aim 2) for these modalities in order develop a method of assessment independent of direct mortality reduction, by using stage and symptomaticity at time of diagnosis in a setting with the capacity to support this research. Completion of these aims may provide a framework and evidence for the utility and more efficient implementation of new technologies in cancer detection, potentially circumventing the need for longitudinal mortality-based studies. The interdisciplinary collaboration and training environment engaged in the progress of this project will support the applicant?s development and research experience, and will help drive her career as a future clinician scientist.